A quarter window provided in an automobile rear door is disclosed, for example, in Japanese Laid-Open Patent Publication No. 62-265018. As shown in FIGS. 5A and 5B, a quarter window 70 disclosed in the publication has a window panel 71 made of a synthetic resin. The window panel 71 is shaped like a right triangle in a plan view, and includes an opposite side portion, a hypotenuse portion, and a base portion. On a side of the window panel 71 facing inside of the automobile, insert portions each extending along either the opposite side portion (FIG. 5A) or the hypotenuse portion (FIG. 5B) are provided. Each insert portion 72 forms a peripheral portion of the window panel 71, and a holding portion 74 that has a substantially channel-like cross section. The window panel 71 and the insert portions 72 are molded integrally through, for example, injection. A sealing member 73 is integrally coupled to the surface of the window panel facing inside of the automobile with the insert portions 72. The sealing member 73 extends along the entire periphery of the window panel 71. The holding portion 74 is covered by the sealing member 73. The sealing member 73 is formed of a polymer elastic material (rubber or thermoplastic elastomer).
When manufacturing the quarter window 70, the window panel 71 and a division bar 76 are placed in a mold (not shown), and a polymer elastic material is injected into a cavity defined in the mold and cured. As a result, the sealing member 73 is integrally molded with the insert portions 72.
As shown in FIG. 5B, a section of the holding portion 74 at the hypotenuse portion holds a frame flange 78 of the rear door 77. As shown in FIG. 5A, a section of the holding portion 74 at the opposite side portion holds a slider 81 of a rear door glass 80 with a glass run 79 fitted to the division bar 76. Accordingly, the quarter window 70 is installed in the rear door 77, and, as shown in FIG. 5B, the rear portions of the window panel 71 and the rear door 77 are substantially flush, which improves the appearance.
According to the configuration disclosed in the above publication, the holding portions 74 hold the frame flange 78 and the slider 81. The division bar 76 and the base portion of the window panel 71 are pressed into the rear door 77 so that the quarter window 70 is installed in the rear door 77. The inner surfaces of the holding portions 74 are coated with the sealing member 73 made of a polymer elastic material. Therefore, after the quarter window 70 is installed in the rear door 77, the quarter window 70 might come off the rear door 77 due to elastic deformation of the sealing member 73.